Loom attachment for weaving ladder webbing



May 3, 1949. F. D. MURDOCK ETAL LOOM ATTACHMENT FOR WEAVING LADDERWEBBING 3 Sheets-Sheet 1 Filed May 1, 1948 INVENTOR! 'edea-afcfi D ,M

May 3, 1949. F. D. MURDOCK ETAL 2,459,202

LOOM ATTACHMENT FOR WEAVING LADDER WEBBING Fil ed May 1, 1948 3Sheets-Sheet 2 4O 4 V 94 E IN V EN TOR-V May 3, 1949.

Filed May 1, 1948 F. D. MURDOCK ETAL. 2,469,202

LOOM ATTACHMENT FOR WEAVING LADDER WEBBING 3 Sheets-Sheet 3 INVENTOR.%ecieticgnmr c .70 Magyar? Patented May 3, 1949 LOOM ATTACHMENT FORWEAVING LADDER WEBBING Frederick D. Murdock, Harrington, and John A. DeAngelis, Cumberland, R. L, assignors to Harry Dexter Peck, Providence,R. 1.

Application May 1, 1948, Serial No. 24,646

4 Claims.

This invention relates to improvements in a loom attachment for weavingladder webbing. More especially it has to do with an attachment wherebyladder web can be woven on a loom having a so-called stationary weftsupply such .as a spool or bobbin wound with yarn.

Ladder web is made for use in Venetian blinds and has two main tapeswhich are woven simultaneously and two systems of cross threads whichgenerally extend parallel to the warp threads of the main tapes and atpredetermined areas are interwoven with first one and then the other ofthe main tapes. Thus at all times during the formation of the ladder webthere are two sheds, one for each main tape, and during the binding-inof the cross threads to a main tape there is what may be deemed anadditional shed formed by the warp threads of the main tape and thethreads of one of the systems of cross threads. This multiplicity ofsheds makes it necessary to insert the filling threads in such mannerthat there will be no interference with the numerous warp threads andthe systems of cross threads. To accomplish this, the present inventionresides in an improved attachment of the type disclosed in the ClutsomPatents, No. 2,130,636 of September 20, 1938, No. 2,229,011 of January14, 1941, and No. 2,258,538 of October '2, 1941.

The primary object of the-present invention is to provide improvedmechanism for eiiecting the desired movements of a pair of thread armscarrying the filling threads and a pair of needles which co-operate withthe said arms to the end that ladder web may be woven on a loom withoutemploying any shuttles and have a knitted selvedge at both edges of themain tapes.

The best mode in which we have contemplated applying the principles ofour invention is shown in the accompanying drawings, but these are to bedeemed illustrative for it is intended that the patent shall cover bysuitable expression in the appended claims whatever featuresof'patentable novelty exist in the improvements disclosed.

In the accompanying drawings:

Fig. 1 is a perspective of an attachment embodying the presentimprovements;

Fig. 2 is a side elevation;

Fig. 3 is a plan;

Fig. 4. is an elevation of the side opposite to that shown in Fig. 2;

Fig. 5 is an endview showing the thread arms at one end of their travel;

Fig. 6 is a view -like Fig. 5 but showing the thread arms at theotherend of their travel; and

Fig. 7 is a side view, similar to Fig. 2, but with some parts removed.

Referring now to the drawings, and more particularly to Fig. 1, thewoven ladder web A with its upper and lower main tapes a and b is shownlying along the top surface of a base [0 which is secured to some fixedmember l2 of a loom. The woven web extends from a guide I4 which issecured to an upstanding bracket portion Illa of the base Hi. This guidehas a slot Ma (see Fig. 5) from the front edge of which various warpthreads extend to the slay it of the loom. The warp threads 0 and d ofthe upper tape a form one shed and the warp threads e and f of the lowertape 12 form another shed. Between these two sheds extend two separatedsystems of other warp threads 9 and it, one system being near one edgeof the web and the other system near the opposite edge (see Fig. 3). Atpredetermined intervals, these warp threads 9 and h are interwovenalternately with the threads of the upper and. lower main tapes to formso-called stitchingareas. Between these areas, the warp threads 9 and hextend or float between the main tapes to form the ladders or so-calledcross threads of the Web; At each stitching area the warp threads of oneor the other of the systems g and h are shifted so as to form anadditional shed, more or less coincident with the shed of a main tape,

so that the filling thread of the main tape will interweave with theso-called cross threads and bind them to the main tape.

The filling threads 2' and a of the main tapes are drawn from thebobbins or spools (not shown) and threaded through the eyes 20a and 22aof a pair of thread arms 2%, 22 respectively. These thread arms arepivotally mounted by studs 26 and it on a bracket plate 28 secured to abracket 36 that in turn is pivotally attached by a shoulder screw 32 toan ofi-set arm Nb of the base ill. An elongated arm Ztc'toi thebracketplate projects betweens a pair of screws'al i, at upstanding froma block 38 mounted on a slide bar Ml of the loom. As the slide barreciprocates, the .thread arms 2t and 22 are caused to swing about theaxis of the shoulder screw 32, and thus carrythe respective fillingthreads i and a from one edge of the tapes to the other.

In addition to this horizontal swinging move ment of the thread armscaused by the reciprocation of the slide bar til, it is a feature of thepresent improvements that the. arms are simultaneously caused to swingvertically about the movements of the arms bring their eyes 28a andbracket bar 44 whose head portion a is secured to the cam and whose legs44b and c are secured at their ends to the bracket portion Illa.

Each thread arm is preferably provided with a roller db which liesbetween the cam 42 and a leg Moor tide of the bracket bar, each rollerguides for a slide it to which the needle holders are pivotally attachedby stub shafts II and i9.

Y The slide I6 carries an outstanding stud 80, on

being supported by a suitable bracket 48 attached to the respectivethread arm. As the thread arms are swung counter-clockwis by themovement of the slide bar dd, the rollers 46 roll along the oppositefaces of the cam 42 being urged thereagainst by a tension spring sowhose ends are secured to the two thread arms. During the clockwiseswing of the thread arms the rollers likewise roll along the cam faceswhich cause the arms to spread apart in a vertical direction.

This combined horizontal and vertical swinging movement of the threadarms is important because it enables the eye ends of the arms to passinto the rather shallow sheds formed by the warp threads and d and e andf of the main tapes, and the additional sheds formed at times'by thewarp threads 9 and h of the systems of cross threads. These sheds areformed rather rapidly and, as just noted, are rather shallow butvnevertheless the described movement of the thread arms enables them toenter and pass through the sheds and then be withdrawn withoutinterference with the numerous warp threads of the main tapes and crossthreads.

As the filling threads are carried through the sheds in thecounterclockwise swing of the thread arms, they are brought intoengagement with a pair of needles 52 and 54. Each needle is preferablyof the type having a latch, 52a and "a, which, when a needle is movedforward, is swung to open position as seen in Fig. 2. This enables thefilling thread carried by a thread arm to slip past the hook, 52b and54b of the needle as the arm nears the end of its counter-clockwiseswing and then engage the hook as the thread arm begins its return orclockwise movement. Thereupon the needle is moved rearward and duringthis movement its latch swings over onto the hook to form an eye inwhich the filling thread just received there is retained, while afillingthread previously laid in the hook (and then withdrawn therefrom andslipped along over the open latch during the forward movement of theneedle) can now slip over the closed latch and oil the needle to bedrawn tight against the edge warp threads of a tape.

The forward and rearward movements of the needles must be accuratelytimed with the movement of the'thread arms and in addition each needlemustbe vertically displaced to bring its hook into position to beengaged by a filling thread. The needles 52"and54 are separately mountedat the ends of needle bars or holders 56 and 58 which have outstandingstuds 60' and i2 carrying rollers 64 and 66 (see Figs. 2 and '7).

These rollers roll in cam slots 68, of a cam plate 12 secured to a plate14 mounted on the base I0. At the top and bottom edges of this plate 14are guide strips 14a, 14b, 14c and "d (see Fig. .7)

which is a roller 82 which can roll on the surfaces of a slot v84 in aplate 88 that is attached to the plate 14. The stud 80 is connected bylinks 88 and 90 with a rockshaft (not shown) of the loom.

As the'needie holders are moved toward the left, as seen in Fig. l, theneedles 52 and 54 are at first moved slightly toward one another tocause the filling thread that is within each hook to move outwardtherefrom and push the respective latches 52a and 54a rearward on theneedles as the latter slides along'the loops of the filling newly laidfilling threads, v turned to engagement with the hooks of the needles toform an eye in which the newly laidthreads. This movement of the latchesis'also augmented by brushes 92, 94 .carried by pivoted arms 96 and 98mounted on a fixed cross plate Hill. These brushes are normally held inposition to be engaged by the latches as the needles move forward. Whenthe filling thread loops are clear of the hook, the needles then beginto separate, due to the shape of the cam slots 68 and 10, and are thusbrought into position at the ends of their leftward movement to presentthe open hooks of the needles ahead of the new filling threads that arebeing laid by the thread arms.

These positions of the needles are shown in Fig;

2. As the thread arms begin their clockwise swing. the respectivefilling threads engagethetween the warp threads during the clockwiseswing of the thread arms;

While the thread arms are completing their clockwise swing, the needlesare moved to the right, as seen in Fig. .2, carrying with them the Thelatches are refilling threads are retained as the needles continue tomove to the right The loops of the previously laid filling threads stillaround the needles are held against return movement with the needles bythe face He of the plate 14, and as a result these previously laidfilling threads slip of! the needles and engage the warp threads at theedges of the respective tapes, thus forming a knitted selvedge edge oneach tape of the ladder web. The movement of the needles is so timedthat the filling threads slipofl. before the thread arms have completedtheir clockwise swing, thus enabling the filling thread to be drawnsnugly against the warp threads of the tapes.

We claim:

1. An attachment for looms having stationary weft supplies and adaptedto weave ladder web,

a pair of thread arms for carrying weft threads threads, a pair ofreciprocally movable needles arranged to operate with said. thread arms,cam means associated with said thread-arms, for caus-'- ing said arms tomove toward one anotherv as another as they carry the weft threads inthe other direction through the'sh'eds, and other cam means associatedwith said needles for causing said needles to move away from one anotheras they move forward into cooperative action with said thread arms tobring the eye of each needle between a thread arm and the weft threadcarried thereby.

2. An attachment for looms. having stationaryweft supplies and adaptedto weave ladder web,

a pair of thread arms for carrying weft threads bacl; and forth throughseparate sheds of warp threads, 9. common axis about which both arms areswung duringoperation of the loom, a bracket movable about said commonaxis, and other axes carried by said bracket about which other axes thethread arms are swung toward and away from each other as they are swungabout'their common axis, and cam means controlling the swing of saidarms about said other axes and so disposed as to cause said arms toapproach one another during one direction of swing about the commonaxis, and to move apart during the reverse direction of swing about thecommon axis.

3. An attachment for looms having stationary weft supplies and adaptedto weave ladder web; a pair of thread arms for carrying weft threadsback and forth through separate sheds of warp threads, a bracket forsaid thread arms rotatable about the axis of a fixed pivot on said loom,and carrying a pair of pivots with axes arranged at right angles to theaxis of said fixed pivot, said thread arms being separately rotatableabout the axes of said pair of pivots while rotatingtogether about theaxis of said fixed pivot; and a V-sh'aped cam mounted on said loombetween said thread arms for engagement thereby, the said cam being sodisposed that as the thread arms swing in one direction ofrotation'about the axis of said fixed pivot they are caused to movetoward one another while rotating about 30 the axes of said pair ofpivots, and as the thread arms swing in the opposite direction ofrotation about the axis of said fixed pivot they are caused to move awayfrom one another while rotating about the axes of said pair of pivots;there being means for maintaining the said thread arms in contact withthe effective surfaces of said V- shaped cam.

4. An attachment for looms having stationary weft supplies and adaptedto weave ladder web, a pair of thread arms carrying separate weftthreads back and forth between separate sheds of warp threads to weavesimultaneously the main tapes of said web; means for swinging saidthread arms together across said sheds and simultaneously swinging thearms toward one another to bringthe eyes of said arms opposite the innerportion of the respective sheds upon the completion of the swing of saidarms in one crosswise direction of movement; a pair of needles mountedfor reciprocal movement beside the edges of said sheds whereat the eyesof said needles are brought closest together; and means controlling thereciprocal movement of said needles to bring them at one end of theirstroke respectively above and below the said thread arms and between athread arm and the weft thread carried thereby.

- FREDERICK D. MURDOCK.

JOHN A. DE ANGEL-IS.

No references cited.

